Prognostic Meteorological Discussion
Issued by NWS
Issued by NWS
749 FXUS02 KWBC 302015 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 315 PM EST Sun Nov 30 2025 Valid 12Z Wed Dec 03 2025 - 12Z Sun Dec 07 2025 ...Heavy rains Thursday into this weekend for parts of the Gulf Coast and Southeast... ...Overview... Sprawling deep and cold low persists over Hudson Bay well into next week. This will maintain below normal temperatures for the central and eastern U.S. Upper ridging enters the Pacific Northwest midweek and will expand at times over The West allowing above normal temperatures to return there. Upper troughing over the Southwest Wednesday will slowly shift east over the southern Plains through Friday which will promote heavy rain chances downstream along the Gulf Coast and Southeast Thursday into this weekend. Wintry weather potential is increasing on the north side of the precipitation shield with a possible nor`easter for the Northeast this weekend. ...Guidance/Predictability Assessment... The positively-tilted Southwest trough will slow as it pivots east Wednesday, likely not crossing the southern Rockies until Thursday night per the 12Z global consensus. This will leave ample time for reinforcing shortwave energy to merge in and allow some development of the trough as it shifts east into this weekend. The 12Z ECMWF remains most bullish on a nor`easter developing over the Northeast this weekend with more suppressed solutions in the ECAIFS and other with a more zonal solution a the surface low shifting straight offshore. Will need to monitor the weekend winter storm potential. The morning WPC forecast relied on deterministic guidance that most closely resembled the 06Z ECAIFS which was a general model blend through Day 5, then more heavily on the 00Z ECMWF along with the 00Z ECENS/CMCE for Days 6/7. The strong deterministic agreement allows for increased confidence in heavy rain along the Gulf Coast Thursday, spreading east into the Southeast/Georgia this weekend. WPC QPF involvement of the 00Z ECMWF to amend the 13Z NBM along with targeted inclusion of the 00Z CMC/UKMET and the 06Z ECAIFS/GFS. ...Weather/Hazards Highlights... Lake effect snow lingers over the Great Lakes into Thursday as mountain snows occur over the Rockies. Heavy rain begins late Wednesday night along the Texas Gulf Coast, spreading over the Central Gulf Coast Thursday, spreading east over the rest of the Gulf Coast into the Southeast Friday into the weekend. The Day 5 Marginal Risk was expanded a bit to include more of the Houston and New Orleans metros per guidance consensus. Low pressure likely develops near the East Coast this weekend, though the direction of the track (whether straight out to sea or northeast along the coast) remains uncertain, so stay tuned for potential winter weather this weekend. Surges of below average temperatures continue for the central and eastern U.S. into next week as the sprawling low over Hudson Bay persists. A surge from the northern Plains through the Northeast occurs Wednesday to Friday with max temperatures of 15 to 25 degrees below zero. Wind chills of -20 to -30F are forecast for portions of the northern Plains and Upper Midwest Thursday morning. The next cold surge may be of similar magnitude and should follows a similar track this weekend. Temperature relief comes to The West with ridging and above normal temperatures expected across the Southwest through the Great Basin late week through this weekend. Jackson Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast (QPF), excessive rainfall outlook (ERO), winter weather outlook (WWO) probabilities, heat indices, and Key Messages can be accessed from: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$